Spray nozzles of the foregoing type have been known for many years, but have been problem prone. Such spray nozzles, for example, commonly are used for spraying slurries or like liquids containing solid phase materials which may be restricted by the swirl passageways defined by the vane. While it is desirable to design the vanes of such whirl spray nozzles for maximum free passage, namely with passageways that will permit passage of solid balls, corresponding in diameter to the final discharge orifice of the nozzle, problems in the vane design remain. For example, if the nozzle body and/or vane structure is a cast part, variations in casting tolerances can adversely effect the maximum free passage of the nozzle. Efforts to increase the size of the vane passageways to compensate for such tolerances can adversely effect the desired flow rate of the nozzle. Furthermore, while it is desired that the discharging spray distribute liquid particles in substantially uniform fashion through out the conical spray pattern, prior spray nozzles with such whirl and turbulent parting vanes can create spray patterns with uneven liquid distribution or with flutter, i.e., the angle of the cone being unsteady and varying during spray operations. Moreover, flutter problems become more pronounced as the angle of the conical spray pattern becomes wider.